Attention sink support for LLM runner #1750

Job	Run time
test-qnn / test-backend-linux (qnn, models) / linux-job	26m 32s
test-qnn / test-backend-linux (qnn, operators) / linux-job	14m 11s
test-qnn / test-backend-macos	-1s
test-qnn / package-golden-artifacts	2m 25s
	43m 7s

Provide feedback